Micro- and nano-structures with small size and high precision can be processed as the micro-/nano-processing technology continues to improve. For example, solid-state nanopores are used in single DNA molecule analysis. The solid-state nanopores have significant advantages in terms to chemical, thermal and mechanical stabilities compared to conventional bio-nanopores for single DNA molecule analysis, and can be manufactured by conventional micro-/nano-processing techniques. As such, nanopores can be processed in a large scale, and pore size can be precisely controlled. Therefore, many researchers keep focusing on the processing of the solid-state nanopores and study the movement of biomolecules in the solid-state nanopores.
Current-carrying electrons on gold nanoparticles or gold nanorods will continuously oscillate when exposed to visible light and near-infrared light, resulting in local plasmon resonance on the surface of gold nanoparticles or gold nanorods. Such local plasmon resonance gradually decays in the form of radiation and non-radiation, and the latter can heat tiny particles to form hot spot with temperature up to 2000° C. This effect has been applied to the processing of nanopores on materials such as glass, polyethylene terephthalate.
However, there exists a difficulty that the diameters of gold nanoparticles are required to be much smaller than the wavelength of light, enabling the gold nanoparticles to absorb the energy of light as efficiently as possible and to generate a high-temperature hot spot for eliminating the materials. Therefore, gold nanoparticles with a diameter of 10-100 nm are usually processed. Accordingly, the diameter of the processed nanopores is also strictly limited to 10-100 nm. In addition, the motion trajectory of gold nanoparticles is random to some extent since the gold nanoparticles are affected by the evaporation of the substrate during processing. Thus, it is very challenging to control the motion trajectory of gold nanoparticles during processing so as to process the gold nanoparticles into shape-controllable pores. In summary, there is a need for a new solution to controllably process nanopores above 100 nm.